Poseidon

The Greeks thought of Poseidon
as a god of violent, unpredictable movement.
He is most often the god of the ocean, which is of course the biggest,
most unpredictable, and most dangerous thing around. Many Greeks spent
a lot of time sailing on
the ocean, and they paid a lot of attention to Poseidon.

But Poseidon is also the god of earthquakes,
and earthquakes are also very common in Greece. He stamps his foot,
or he hits the earth with his trident (like a pitchfork) to make an
earthquake.

And, maybe for the same reason, Poseidon is the Horse-God. Horses,
I suppose, are also big and unpredictable and dangerous, though not
on the same scale as earthquakes and oceans. If he came with the Indo-Europeans
to Greece, then he might have originally been a horse-god, who only
later came to be associated with the ocean and earthquakes.

Poseidon, in Greek mythology, is the brother of Zeus
and Hades, and so also the brother of Demeter
and Hera. Like them, he is the child of Earth
and Time, Gaia and Kronos.

More great articles:

There are not very many stories involving Poseidon.
One is the story of Phaedra,
which shows Poseidon more or less as a blind, uncaring force, rather
like the oceans and earthquakes he controls. Another is the Odyssey.
You might think of Poseidon as representing physis,
nature, in the Greek mind, and that when people sacrifice to Poseidon
they are trying to control nature, to reduce chaos to rationality, to
establish nomos, or law. For people who sailed on the ocean in tiny
wooden ships, the idea of being able to control the ocean might seem
very interesting!

To find out more about Poseidon, check out these books from Amazon
or from your local library:

Greek
Religion, by Walter Burkert (reprinted 1987). By a leading expert,
for adults. He has sections on each of the Greek gods, and discusses
their deeper meanings, and their function in Greek society.